It is several years already I trying some Air Quality monitors. And I think it is time to post some of the results. So here it is. Overview of some Air Quality monitors tested so far.
For me perfect device is the one:
measure correctly
measure multiple parameters
display information locally
has a battery and can be used as a mobile tool
is an IoT device with Wi-Fi connectivity and mobile app
not cost a fortune
quiet
Some of the requirements are cannot (or at least not easy to) be met simultaneously. A lot of advanced sensors with Wi-Fi connectivity and good mobile application make the device expensive. Battery and battery charging circuits usually affect temperature and relative humidity measurements. Active airflow improves measurement speed and quality but makes devices noisy. So there is no single perfect device yet to cover all Air Quality Monitor use cases. That is why I choose some devices I like more by category.
IoT Air Quality Monitors
Best IoT Air Quality Monitor “award” goes to AWAIR 2
So as you can see above the device is not perfect. It is noisy, that is how good airflow and better measurement quality and speed achieved. Some Sensors are not the best in class, that is how the price is lower than 200$. For more details see AWAIR 2 Review.
IoT Alternatives
uHoo
✔️ quiet, more parameters (CO, O3, NO2), iPad app ❌ expensive (330$), cheaper sensors, no local display
AirVisual Pro (Node)
✔️ large display, outdoor data for PM2.5, battery, iPad app ❌ more expensive (280$), fewer parameters (no VOC)
Netatmo Smart Home Weather Station (Urban Weather)
✔️ quiet, weather station (external t/RH module), iPad app, 180$ ❌ fewer parameters (no PM2.5, no VOC), poor CO2 sensor
Again, as it was with the best IoT device, this one is not perfect. It is noisy, it has no Wi-Fi/Bluetooth/etc, humidity measurements may show -10% RH on high humidity tests, but still, it is better than some others and good for the price.
Old school device with separate analog temperature and humidity sensors, Old model of CO2 sensor. No other air quality sensors present. Need to be always plugged. But still one of the best in measurement quality.
As for the January 2020, there are 10 CarPlay enabled navigators available in Ukrainian AppStore. See twenty iOS Navigators 2020 comparison. That is about 50% of all. Some new applications were found since iOS Navigation 2016 comparison in November 2016. So trends are as following. Much more OpenStreetMap based application. Even apps with own maps (like Apple map) use or get some data from OSM. Free applications are in general better. So there is clear wikinomics at work. Maps and Traffic data quality are better with the mass collaboration approach. In 2020 there is almost no reason to use paid navigation and that is probably why most old-school “best in class” navigators like iGo are not in active development anymore. Also, there are fewer local apps on the market.
How to choose a navigation app for your region:
Map is actual (new streets, new buildings, etc)
Traffic information is available and good
The Map can be edited by users
Users are able to report traffic events
CarPlay and iPad support (if needed)
User Interface is good
Free or price is reasonable
Offline maps available
Waze
Best iOS navigation application for Kyiv right now.
Dienmern DM601 is a portable air quality monitor with two options available DM601A and DM601B. The difference is in additional HCHO sensors. Model DM601A has no HCHO sensor onboard.
The device has SHT30 temperature and humidity sensor but measures temperature wrongly due to device self-heating and poor thermal design (see thermal photos of DM601A). The battery is 3000 mAh that gives about 5 hours of both charging time and battery life (see details).
Most of the sensors inside DM601 are unbranded. No Wireless connectivity. Usability is average. Measurements (except temperature) are more or less ok.
Multi-sensor (CO2, PM2.5, TVOC, HCHO) air quality monitor with Bluetooth and Wi-Fi.
Applications are available for iPhone, iPad, Android phones.
By its design Air Mentor is not a portable IoT device. It has no battery. It has no display. So it is an alternative to uHoo (and to some extent to Netatmo). If compare Air Mentor 2s to uHoo: Air Mentor 2s have HCHO sensor. But uHoo measures CO, O3, NO2, pressure instead. Netatmo is actually a weather station with an external t/RH sensor, that also measures air quality by CO2 parameter only. Air Mentor 2s got a more expensive CO2 and t/RH sensors than both Netatmo and uHoo.
Temperature and Humidity sensor (SHT30) is both good itself and placed correctly on the bottom of the device with some gap from the mainboard. More or less as it is recommended by the Sensirion guide.
There are some issues with the current versions of mobile applications. For example, you cannot connect the device to Wi-Fi access points using iOS devices (it works using the Android version). Russian localization is not complete. Trend data from cloud not always loading (for both iOS and Android).
Hti HT-401 is the most portable CO2 meter I have. It is small and simple. It is only 75 mm in diameter and 25 mm in depth. Weight is 62 g. That is including 14250 (1/2AA) 300 mAh battery. Its only button is power. It count 30 seconds before actually show the CO2 level. And it automatically power off after 30 minutes.
Four-digits LED display only shows CO2 level and 3 emoticons ?<600ppm ?600-1200ppm ?>1200. That is it. No settings for emoticons limits. No setting for the power-off timer. Not display temperature and humidity, nor time and date. Just one sensor inside and that is well known SenseAir S8 LP. That provides correct readings. Changing the environments not impact accuracy. The device is relatively cheap (I bought it for about 75$ without battery on Aliexpress)
Since USB 2.0 became a standard for charging port there are a couple of things happens. Devices got more and more battery capacity and that is why many fast charging protocols appear to overcome USB 2.0 default 2.5W (5v 0.5A). Those protocols were necessary to keep the same charging time with larger batteries. Some of those protocols were part of USB standard (like USB Battery Charging and USB Power Delivery) and some were not (like Apple 2.4A, Qualcomm QuickCharge, Mediatek PumpExpress+, and a lot of others).
Most chargers and power banks support only some of those fast charging protocols. So usually you will not get the fastest posible charging for all of your devices from the same source. For example power banks with Mediatek PumpExpress support is exceptionally rare devices. There are a number of power banks with Qualcomm Quick Charge or USB Power Delivery available, but not with Mediatek PE+. So below is three 10000 mAh power banks I found with MTK-PE support.
Power-Z KM001C is USB Type-C tester from ChargerLAB. Nice and slim. With OLED display. With good PC Software. Have similar features to KM001 and same PC Software.
The main issue of Power-Z devices is no good English translation for both firmware and PC Software, But anyway it still a useful tool. And PC Software is actually best in class. Software updates are available at dropbox folder. Firmware update available from PC Software.
This time OCRKJ D9-H. Which also can be found in some shops as unbranded LCD Digital Air Quality Monitor (AKA monllac, AgoHike, Robincure). Similar to OCRKJ K6-D from the previous review. It was bought for about 100$. Yet another portable device with 10 hours battery life and correct CO2 measurements.
Pros
3000 mAh battery ( 10 hours of battery life)
additional sensors (HCHO, VOC and PM2.5)
16 different screens including trends
Active airflow with the relatively quiet fan
quality design and schematic inside (no glues, connectors, replaceable sensors)
good CO2 sensor inside – SenseAir S8 LP
Cons
slow charging – 8 hours (in operation mode)
no connectivity (Bluetooth, wi-fi, USB mass storage)
no ambient light sensor
unconfigurable high CO2 limits (GOOD is up to 1000 ppm)
wrong temperature and RH measurements (+3C, -10%RH)
It looks like relatively cheap SHT20 temperature and humidity sensor inside make it sort of a lottery if you will get correct measurements or not.
